Fix for TV Overscan in Ubuntu with Nvidia Drivers

Ok, this problem has been a consistent thorn in my side for as long as I've been running Ubuntu on my TV (a number of years). On a lot of HDTVs, setting your computer to display 1080p or 720p or whatever will often cut off the edges of the screen. This cutoff is known as overscan and it used to be necessary because all sorts of garbage data would be displayed in the edges of broadcast signals and video games. Nowadays, that doesn't happen and we want to see every bit of the picture but many TVs still do it.

The easiest fix on TVs of any reasonable quality is to set the TV to "just scan" or "pixel perfect" mode (it goes by many different names depending on manufacturer). However, if your TV is cheap/crappy, you won't have such an option and the only way to deal with it is via software. This works just dandy in Windows, where the Nvidia driver has a handy little "overscan compensation" option where you can adjust a slider until your entire desktop is visible.

Sometimes, depending on driver revision and apparently some other unknown (to me) factors, a similar slider is available in the nvidia-settings applications in Ubuntu. This is undependable, though, and it will sometimes be grayed out or even disappear after you've used it in the past! :O

If you run into any of this, the way to fix it is to add a line to your /etc/X11/xorg.conf files that invokes the ViewPortIn/ViewPortOut options in the driver. So, open a terminal and type:

sudo nano /etc/X11/xorg.conf

You should see:

Section "Device"        Identifier    "Default Device"        Option        "NoLogo"       "True"EndSection

Or something similar. If you don't see any of that (e.g., if your file is totally empty), then just add it in manually.

Next, add a new line under the "NoLogo" line that looks like this (all one line, btw):

Option    "metamodes" "DFP-0: idealxresolution { ViewPortIn=idealxresolution,ViewPortOut=desiredxresolution+excessX+excessY }"

So, if, like me, you want it to run in 720p with 24 pixels of horizontal overscan compensation added to left/right sides and 14 pixels of vertical overscan compensation added to top/bottom, your line will look like this:

Option "metamodes" "DFP-1: 1280x720 { ViewPortIn=1280x720,ViewPortOut=1232x692+24+14 }"

Now, you'll notice that the buffers I've added to the end are exactly half of the total amount of resolution I'm chopping off. That's because the specified amount is added to both sides.

You'll also notice that my line uses DFP-1 instead of DFP-0. I'm not sure why that is, but that's what it identifies as in my nvidia-settings application, so be sure to check there first to find out what yours should be labeled as.

Log out and back in and it should use the new resolution. If not, try rebooting.

Cg Pixel Shaders for SSNES

Update (11/08/2012): New shaders added to the end of the post.

In addition to XML/GLSL pixel shaders, SSNES also supports pixel shaders written in Nvidia's proprietary Cg shader language, which is similar in syntax to Microsoft's HLSL language. While Cg hasn't been a very popular language for shaders, historically, many new shaders have been written for use with PS3 homebrew, where Cg is the only supported shader language. In fact, these shaders were downloaded from TwinAphex's SNES9x Next source code repository.

Another benefit to the Cg shaders is that they work with both OpenGL and Direct3D drivers in SSNES, which makes many of the more modern shaders to available to people with poor OpenGL performance for the first time.

As with my previous shader posts, these images were captured at a 3x scale factor, then enlarged using nearest neighbor to 400% for the detail shot. Click the thumbnails to embiggen.

5xBR+CRT

This shader combines Hyllian's 5xBR algorithm with the phosphor-derived scanline shader from Caligari with great results. This shader is designed for use with square, non-aspect-corrected pixels, so be sure to use an 8:7 aspect ratio on SNES to avoid any nasty artifacting. It also expects at least a 5x scale factor, which looks like this:

Here are a few more pictures from the GBA version of Final Fantasy 6 and Street Fighter 3: Third Strike on FBA:

I find the scanlines make text easier to read than with 5xBR alone, for whatever reason.
Download the xBR pack from Hyllian here.

Retro

This shader accentuates the individual pixels by adding a cool, beveled look along with some color-tweaking mojo to give them a feeling of depth. Again, it expects non-aspect-corrected images, or else subpixel aliasing effects will make a mess of things.

Here's another picture at 20x (5x scale factor, enlarged 4x with nearest neighbor; see it full size to get the full effect):


Notable ports from the XML shader family include cgwg's CRT shader, Themaister's dot-n-bloom (listed as 'dots.cg') and Waterpaint shaders and an extremely fast implementation of bicubic filtering (bicubic-fast.cg) from Hyllian, as well as all the classics, such as HQ2x, SuperEagle and so on.

Update (11/08/2012)

CRT-ReverseAA

Hyllian has been working on some interesting shaders lately, including an implementation of Christoph Feck's "reverse anti-aliasing" algorithm, which allows for some very sharp, smooth upscaling. It works on any image but really shines on digitized images with lots of gradients (think: SNES games with digitized sprites or games with prerendered backgrounds, like Resident Evil or Final Fantasy 7). It's also particularly good at rendering legible text, so it's great for RPGs, as well. Here are some images of this shader paired with some scanlines:

 As you can see, Clay Fighter looks really great with this shader. Too bad the game is godawful.

bsnes-gamma-ramp

As with pretty much everything else, bsnes has taken some sophisticated steps to achieve an authentic gamma ramp that reflects the actual appearance of games. Themaister was kind enough to reproduce the relevant code in Cg form. This is how it looks:

He also wrote a cgp file (just a simple file that tells RetroArch how to deal with multiple Cg shaders) that will enable pixel blending used in pseudo-hires transparency, which bsnes-derived emulation cores typically render as a series of vertical stripes instead of the intended translucent color. You can download the bsnes-gamma-ramp+hires blending bundle here.

LCD3x

A simple, fast scanline shader from Gigaherz, LCD3x is intended to evoke the look of handheld console LCD displays:

It's also a very easy shader to customize, if you want darker scanlines or to brighten the overall image. These variables are located on lines 12 and 13 of the shader, respectively.

I'll add more shaders and more pics in the near future.

Nvidia 256.35 Driver on Ubuntu 10.04 Lucid Lynx

(If you just want installation instructions, skip down to the section labeled 'How to Install It')

I don't normally devote entire blog posts to something as trivial as a driver update. In fact, I usually don't update my proprietary driver blob until Ubuntu updates its packages and pushes them out through the software update tool, but this particular driver update has brought about a couple of major changes (for me) that I thought warranted stepping out of my comfort zone a bit.

These features are:

1.) From Nvidia's website, "Fixed an interaction problem between Compiz and 'screen-scraping' VNC servers like x11vnc and vino [ed.: the VNC server that Ubuntu uses by default] that caused the screen to stop updating."

This bug has been around since Hardy Heron and has been a thorn in my side. The only workarounds were to use a different VNC server (big hassle), constantly close/reopen the VNC connection to manually refresh (even bigger hassle), or switch to metacity instead of Compiz whenever you want remote access (not a huge hassle, but still inconvenient).

2.) The driver now supports overscan compensation (via a slide-control in the nvidia-settings application) for displays that have overscan issues, though this isn't mentioned in the changelog specifically.

This feature has been in the Windows driver control (and the Linux Catalyst driver for ATI users) for a very long time, but it is new for the Linux Nvidia driver and solves another long-standing issue for me. Now, I no longer need to cover the screen edges with transparent GNOME panels to keep new windows from drawing offscreen or worry about toolbars getting chopped off of fullscreen applications. W00t! (Edit: overscan compensation has been in the driver since Karmic, but it never showed up for my specific card until this latest driver).

The new driver also includes a host of new VDPAU improvements, which always a good thing.

How to Install It

Update (7/27/10): If you don't feel like doing all of the steps I have laid out, there's a handy PPA provided by the same cats who package the standard Ubuntu graphics drivers that has a package for the 256.35 driver. You can find it here. Whether you use the PPA or my steps, the Bonus sections below are still applicable and handy.

I have an Nvidia 8600 GT graphics card and, when I first tried to install the driver, I followed the procedure that has always worked in the past of simply downloading the installer, dropping down to console, and running the installer. However, when I tried that, the installer failed with the error "THE DISTRIBUTION-PROVIDED PRE-INSTALL SCRIPT FAILED." Others have apparently also gotten another error, which I will include here for search engine purposes: "Error: Unable to load the kernel module 'nvidia.ko'. This happens most frequently when this kernel was built against the wrong or improperly configured kernel sources, with a version of gcc that differs from the one used to build the target kernel, or if a driver such as rivafb/nvidiafb is present and prevents the NVIDIA kernel module from obtaining ownership of the NVIDIA graphics device(s), or NVIDIA GPU installed in this system is not supported by this NVIDIA Linux graphics driver release."

In either event, these steps should clear things up:

1.) First, we'll gather some resources: download the driver from Nvidia's website and put it somewhere, such as your Home directory. Then, open a terminal and type:

sudo aptitude install linux-headers-`uname -r` build-essential nvidia-settings

2.) Now, we need to get rid of some modules that conflict with our soon-to-be-installed proprietary driver. So, in a terminal, type:

sudo gedit /etc/modprobe.d/blacklist.conf

Scroll down to the bottom and copypasta these lines:

# Allows proprietary Nvidia driver to install

blacklist vga16fb

blacklist nouveau

blacklist rivafb

blacklist nvidiafb

blacklist rivatv

Save and exit.

3.) Next, we need to clear out any previously installed Nvidia drivers, so (still in a terminal) type:

sudo apt-get remove --purge nvidia-*

4.) Reboot and, when the error window pops up saying Ubuntu can't load drivers blah, blah, blah, choose to 'Exit to console,' and it should dump you down to a command prompt. Login and navigate to the directory where you put your Nvidia driver installer from Step 1 (if you put it in your Home directory, you should already be there upon login).

5.) Start the Nvidia driver installer by typing (hint: you can use the TAB key to autocomplete instead of using the * wildcard character):

sudo sh NVIDIA-*

When it asks if you want it to automatically configure things, select 'yes' and it will auto-generate an xorg.conf file with the appropriate fields.

Reboot again and everything should be hunky dory (if not, and your installation still poops out, scroll down to the bottom of the post for some more things you can try).

Bonus Points

Unfortunately, if you install the driver this way, each time a new kernel update comes down the pipe, your Nvidia driver will stop working and have to be reinstalled, which can be a big bummer. However, you can set up a script that will run anytime the driver needs to be reinstalled:

1.) First, we'll move our Nvidia driver installer to a safe location. In a terminal, navigate to wherever it is and type (again, use TAB to autocomplete instead of the wildcard):

sudo mv NVIDIA-* /usr/src

2.) Next, we want to make a symlink (kinda like a more powerful shortcut) to the installer so our script won't need to be rewritten any time a new Nvidia driver comes out. In a terminal, type:

sudo ln -s /usr/src/NVIDIA-* /usr/src/nvidia-driver

Now, since our script will reference the 'nvidia-driver' symlink we can just overwrite the old driver and make a new symlink using the same name if there's a driver update.

3.) Now for the script itself. Open a text editor and, in a new file, copypasta this:

#!/bin/bash

#

# Set this to the exact path of the nvidia driver you plan to use

# It is recommended to use a symlink here so that this script doesn't

# have to be modified when you change driver versions.

DRIVER=/usr/src/nvidia-driver

# Build new driver if it doesn't exist

if [ -e /lib/modules/$1/kernel/drivers/video/nvidia.ko ] ; then

echo "NVIDIA driver already exists for this kernel." >&2

else

echo "Building NVIDIA driver for kernel $1" >&2

sh $DRIVER -K -k $1 -s -n 2>1 > /dev/null

if [ -e /lib/modules/$1/kernel/drivers/video/nvidia.ko ] ; then

echo " SUCCESS: Driver installed for kernel $1" >&2

else

echo " FAILURE: See /var/log/nvidia-installer.log" >&2

fi

fi

exit 0

Save the file with the name update-nvidia and exit the text editor.

4.) Now, we want to make our script executable, so, in a terminal, navigate to wherever you made your script and type:

chmod a+x update-nvidia

5.) Finally, we need to install it. Still in your terminal from the last command, type:

sudo mkdir -p /etc/kernel/postinst.d ; sudo install update-nvidia /etc/kernel/postinst.d

Now, you should be all set. Whenever you install a new kernel, this script should kick in and install the Nvidia driver for you.

Even More Bonus Points

Now that we've got our driver installed and ready to update itself, we should consider our power consumption! Usually, the Nvidia driver will default to a power profile that always leaves your card running full-tilt, which sucks battery life and raises your utility bill. Thankfully, there's something we can do about it.

Open up a terminal and type:

sudo gedit /etc/X11/xorg.conf

This will get us into the auto-generated configuration file created by the driver installer.

Scroll down to the Nvidia driver section (you can tell it's the right section because it will be labeled 'Device,' the 'Vendor' field will say 'Nvidia,' and the 'Driver' field will say 'nvidia') and add these three lines:

Option "RegistryDwords" "PowerMizerEnable=0x1; PerfLevelSrc=0x3333"

Option "Coolbits" "1"

Option "OnDemandVBlankInterrupts" "True"

Save the file and exit.

In the first line, the PowerMizerEnable switch tells the driver that we're interested in using the dynamic clocking features (this switch may not be entirely necessary, as PowerMizer is supposed to be enabled by default, but it can't hurt anything and may be required for some cards/cases), while the PerfLevelSrc field tells it which performance level we want to use. The 0x3333 setting means we want dynamic, on-demand clocking for both battery and AC power.

The second option we added enables the 'Coolbits' feature, which lets us manually control the clock and memory speeds on our card via the nvidia-settings application.

The third option enables a checkbox in the nvidia-settings application to allow or disallow vBlank interrupts. Allowing them (checking the box) reduces the number of wakeups from idle, and thus reduces power consumption somewhat.

Now, in my case (8600 GT), there is only one performance level and dynamic clocking does nothing (you can find out your performance levels by typing in a terminal: nvidia-settings -q GPUPerfModes -t). This really stinks, since I do all of my gaming in Windows and all I really need my video card for in Ubuntu is compositing and fancy desktop effects. With this in mind, I used the Coolbits option via the nvidia-settings application to drastically underclock my card. It now runs at approximately 150 mhz on the core clock and 180 mhz on the memory, which generates far less heat and uses way less power than before. Compiz still looks great and has no performance issues, even while playing HD video, rotating the desktop cube with 3D windows, etc.

If Installer Still Fails

(I didn't have these problems, so I didn't try these instructions myself. They are only here in case you need them)

So, if the above instructions didn't work, we still have some things we can try:

1.) Drop back down to the command line (by pressing Alt+F1), login and type:

sudo gdm-stop

and then

sudo apt-get remove --purge xserver-xorg-video-nouveau

2.) Now, we need to fiddle with some blacklisted framebuffer stuff, so type:

sudo nano /etc/modprobe.d/blacklist-framebuffer.conf

Once in, we need to comment out (put a # in front of) blacklist vesafb and add a new line that says:

blacklist vgafb16

Save and exit (hit ctrl+x).

3.) Now, type:

sudo nano /etc/initramfs-tools/modules

Scroll down to the bottom and add these two lines:

fbcon

vesafb

Save and exit, then update the initramfs by typing:

sudo update-initramfs -u

4.) Now, we need to tell grub about our framebuffer, so type:

sudo nano /etc/default/grub

Once in, search (ctrl+w) for GRUB_CMDLINE_LINUX= and add either vga=771 or vga=795 (which one you'll add depends on your resolution, so for now, just pick one). Save and exit, then update grub by typing:

sudo update-grub

If things are messed up, you can redo the above step using the other vga value to hopefully correct things.

Now, once you reboot, you should be able to pick back up from Step 4 in the original instructions and install the Nvidia driver normally without any further errors.